How Many Attended The Tea Parties?

Below is a VERY long (but far from comprehensive) list of crowd size estimates at today’s Tea Party protests across the country. I’ve tried to take estimates provided by reporters or police officials only, rather than estimates provided by the organizers or attendees themselves, although surely this is an imperfect science. I’ve also tried to avoid taking any data from explicitly partisan (including left-leaning partisan) news sources. Collectively, these reports account for an attendance of 111,899.

Are these figures impressive? I’d say they’re reasonably impressive. Then again, 111,899 isn’t much more than the number who attend a typical University of Michigan football game or who attended a single Barack Obama rally in Portland, Oregon last year.

But, the list is far from complete. This covers 126 rallies, whereas the most common figure I’ve seen is that there were about 750 such protests nationwide — about six times more than we’ve accounted for.

So, can we simply multiply the estimate by six to estimate the overall number of attendees across the country, which would imply that about 670,000 tea-baggers?

That strikes me as pretty bad idea, because there is a statistical bias in which rallies are reported upon — more successful rallies in larger areas are liable to draw more reporters, and thereby show up in news feeds, etc. Although there are a few large rallies (Atlanta, for example) where there aren’t yet hard numbers to account for, I’d imagine that most of the “missing” protests in the long tail drew relatively small numbers — 20, 50, 100, 200 people. My hunch is that the overall attendance figure nationwide is probably something like 250,000, but that’s just a guess.

The other weird thing about these numbers is how little correlation there seems to be between the size of the rally and the size of that city’s population — the Olympia, Washington event drew about 20 times more people than Philadelphia’s; twice as many showed up in Baxter, Arkansas as in Boston. These rallies appear to be drawing disproportionately from rural areas, which is one reason why, although the cumulative attendance figure is impressive, there doesn’t appear to have been any one single place where the protesters gathered (say) 15,000 people together.

Nate Silver is the founder and editor in chief of FiveThirtyEight. @natesilver538